1. Field of the Invention
This invention relates to an apparatus and a method for recognizing the state of connection of terminals, for recognizing the connection state of a plurality of terminals of a memory device having a non-volatile memory unit (or non-volatile memory), such as a flash memory mounted thereto, and for detecting a fault concerning the connection of the terminals, i.e., connection fault of the terminals.
In computer systems in general, including personal computers, a memory device having a non-volatile memory unit, such as a flash memory, mounted thereto, for example, a small size memory card, is used in computer systems while the memory card is assembled into an adapter of an industrial standard form and the adapter is inserted into a socket portion used for the personal computer, etc. To confirm the state of connection of a plurality of terminals extended from the memory card with the socket portion, it is customary to test the state of connection between a plurality of terminals and the socket portion by using a measuring instrument such as a tester to detect any connection fault of the terminals, before the computer systems, including personal computers, etc, are shipped as products. It is desirable, however, that the state of connection of terminals can be tested even in an environment in which a measuring instrument such as a tester is not available, e.g., an environment in which a user carries out a test after the shipment of the products, in order to prevent an erroneous operation of the computer systems resulting from the faulty connection of address terminals, data terminals, and so forth.
The present invention provides a technique for easily detecting a connection fault, such as a short-circuit and an open fault at a part or parts of address terminals, data terminals, and so forth, even in the environment in which a measuring instrument such as a tester is not available. However, the above technique is based on the premise that read operations can be normally carried out from the memory card.
2. Description of the Related Art
In order to make the problem with the conventional method for recognizing the state of connection of terminals more easily understood, a method for detecting the connection fault of terminals of a memory card according to the prior art will be explained with reference to FIGS. 1 and 2 that will be described later in "Brief Description of The Drawings".
In FIG. 1, a plan view showing a general shape of an adaptor having a memory card mounted thereto is illustrated. In FIG. 2, a block diagram useful for explaining a conventional technique for recognizing the state of connection of terminals according to the prior art is illustrated.
To use a non-volatile memory unit 100, such as a flash memory, for a computer system, a small size memory card 60 having this non-volatile memory unit 100 mounted thereto is assembled ordinarily into an adapter 7 of an industrial standard form, as shown in FIG. 1. A plurality of terminals 5 (see FIG. 2) extended from the memory card 60 are formed at a connector portion 70 at an end portion of this adapter 7. These terminals include address terminals A0 to AN (where N is an arbitrary positive integer), data terminals D0 to DM (where M is an arbitrary positive integer such as M=15), control terminals and other terminals. Further, a plurality of terminals of the connector portion 70 are connected to the socket portion 8 when the adapter 7 is inserted into the socket portion 8 (see FIG. 2) for a personal computer, etc. Generally, however, the non-volatile memory unit 100 is of a fit-in type such that the memory unit 100 is fitted into the memory card 60, and the connector portion 70 might be worn out. Therefore, there might be the case in which all of the terminals of the connector portion 70 are not always perfectly connected to the socket portion 8.
Conventionally, the state of connection of the terminals has been recognized by testing a connection state between a plurality of terminals 5 of the connector portion 70 and the socket portion 8 by using a measuring instrument, such as a tester 400, and by writing exclusive test data that is prepared in advance, into a plurality of addresses inside the non-volatile memory unit 100. When this exclusive test data is written at the stage before shipment of the computer system including the personal computer, etc, as the product, that is, the stage before the use of the memory card 60 having the non-volatile memory unit 100 mounted thereto for the computer system, the test data can be erased after the test of the connection state of the terminals is completed and the data on the user side can be written into the non-volatile memory unit 100.
However, when the same test is to be carried out after shipment by using the exclusive test data, after the data of the non-volatile memory unit 100 inside the memory card 60 is expanded (i.e., transferred) to the computer system, i.e., when the state of connection of the terminals must be recognized after an erroneous operation has occurred inside the computer system due to wear of the connector portion 70, etc., the existing data that has already existed inside the non-volatile memory unit 100 must be rewritten so as to write the test data into a plurality of addresses. In other words, to confirm whether or not there is the connection fault in each of the address terminals A0 to AN, the data on the user side that is stored in the non-volatile memory unit 100 must be once erased and the test data must be then written afresh. On the other hand, to prevent the rewriting of the existing data inside the non-volatile memory unit 100, it is possible to employ a method in which this existing data is copied into other memory unit, but a large amount of memory capacity becomes necessary for copying this existing data.
It has therefore been difficult, according to the conventional method for recognizing the state of connection of terminals shown in FIG. 2, to easily confirm the connection state without using the exclusive test data, even when the connection state of the address terminals which are situated only as a part of a plurality of terminals of the memory card, is to be confirmed. In consequence, the problem occurs in that the existing data that has already existed inside the non-volatile memory unit of the memory card must be rewritten and the data on the user side is destroyed.